Active antennas invade next-gen smartphones

SAN JOSE, Calif. – A new class of active antennas is coming to smartphones.

Tunable antennas that can dial in multiple frequencies are getting packed into handsets this year. Prototypes with beam steering are in the lab, promising better coverage and data rates probably next year.

“We have been working for many years on active antennas and are starting to see them adopted now—we’re at the inflection point,” said Jeff Hamblin, chief scientist at Ethertronics (San Diego).

“We should see more tunable antennas in production this year and next,” said Shamblin in an interview with EE Times after giving a talk on the topic at DESIGN West here. “A lot of companies have developed tunable capacitors for antenna tuning, so the components are there and cost effective now,” he said.

Today’s active antennas can adjust impedance and frequency response to cover a set of frequency bands. The versions still in prototype stage can change the length and shape of radiation elements to focus beams in specific directions, maximizing coverage and data rate.

Last year, Ethertronics worked on 200 custom antenna designs for handsets. When active antennas mature it may be possible to define four or five standard antennas that could be used by most devices, saving time and money.

Click on image to enlarge.

The tunable capability is in high demand now. Today’s LTE handsets need to support as many as 40 different spectrum bands to handle key LTE, 3G and 2G services (see chart above). Engineers are still working on how to deliver a commercially viable world phone covering all the global LTE bands, Shamblin said.